Undefined variables are valid. If variables are not defined in the Taskfile, the configuration remains valid — they can be passed at runtime.version: '3'
tasks:
hello:
cmds:
- echo "Hello {{.NAME}}"
Variable Types
Taskfile supports several types of variables:
stringboolintfloatarraymap
version: '3'
vars: # global vars
GLOBAL_VAR: "I am a global variable"
tasks:
display-variables:
vars:
STRING_VAR: "Hello"
BOOL_VAR: true
INT_VAR: 42
FLOAT_VAR: 3.14
ARRAY_VAR: [1, 2, 3]
MAP_VAR:
map:
key1: value1
key2: value2
cmds:
- 'echo String: {{.STRING_VAR}}'
- 'echo Bool: {{.BOOL_VAR}}'
- 'echo Int: {{.INT_VAR}}'
- 'echo Float: {{.FLOAT_VAR}}'
- 'echo Array: {{.ARRAY_VAR}}'
- 'echo {{index .ARRAY 0}}' # outputs 1
- 'echo Map: {{.MAP_VAR}}'
- 'echo Map key1: {{.MAP_VAR.key1}}'
Set Default Values for Variables
version: '3'
tasks:
msg:
vars:
MESSAGE: '{{.MESSAGE | default "Hello World"}}'
cmds:
- 'echo "Message is: {{ .MESSAGE }}"'
ubuntu@touted-mite:~$ task msg
task: [msg] echo "Message is: Hello World"
Message is: Hello World
# Override the default value
ubuntu@touted-mite:~$ task msg MESSAGE="Hi, I'm karchunt"
task: [msg] echo "Message is: Hi, I'm karchunt"
Message is: Hi, I'm karchunt
Dynamic Variables (Shell Command Output)
Use sh to execute shell commands and use their output as variable values. This is useful for dynamic data retrieval such as system info or environment variables.
version: '3'
tasks:
os-version:
vars:
OS_VERSION:
sh: cat /etc/os-release | grep "VERSION_ID" | cut -d "=" -f2
cmds:
- echo "OS version is {{.OS_VERSION}}"
ubuntu@touted-mite:~$ task os-version
task: [os-version] echo "OS version is \"22.04\""
OS version is 22.04
Required Variables
Mark variables as required. If they are not provided, the task will not run.
version: '3'
tasks:
greet:
requires:
vars:
- NAME
cmds:
- echo "Hello {{.NAME}}"
ubuntu@touted-mite:~$ task greet
task: Task "greet" cancelled because it is missing required variables: NAME
ubuntu@touted-mite:~$ task greet NAME=KarChun
task: [greet] echo "Hello KarChun"
Hello KarChun
Restricting Variable Values with enum
Use the enum field to ensure variables only accept allowed values.
version: '3'
tasks:
deploy:
requires:
vars:
- name: ENV
enum: [dev, staging, prod]
cmds:
- echo "Deploy to {{.ENV}}"
ubuntu@touted-mite:~$ task deploy ENV=beta
task: Task "deploy" cancelled because it is missing required variables:
- ENV has an invalid value : 'beta' (allowed values : [dev staging prod])
ubuntu@touted-mite:~$ task deploy ENV=dev
task: [deploy] echo "Deploy to dev"
Deploy to dev
Referencing Other Variables
When passing variables between tasks, using the template engine will convert typed values (like arrays) to strings. Use the ref keyword to pass variables by reference and preserve their type.
Using {{.FOO}} to pass an array converts it to a string. Use ref: .FOO to preserve the array type.
version: 3
tasks:
foo:
vars:
FOO: [A, B, C]
cmds:
- task: bar
vars:
FOO: '{{.FOO}}' # FOO becomes a string
bar:
cmds:
- 'echo {{index .FOO 0}}' # outputs '91' (ASCII for '[') instead of 'A'
Taskfile.yaml — correct approach using ref
version: 3
tasks:
foo:
vars:
FOO: [A, B, C]
cmds:
- task: bar
vars:
FOO:
ref: .FOO # preserves array type
BAR:
ref: index .FOO 1
bar:
cmds:
- 'echo {{index .FOO 0}}' # outputs 'A'
- 'echo {{.BAR}}' # outputs 'B'
ubuntu@touted-mite:~$ task foo
task: [bar] echo A
A
task: [bar] echo B
B
The ref keyword works the same way with deps.
Parsing JSON/YAML into Map Variables
This only works with the ref keyword, not the template engine approach.
fromJson or fromYaml functions to parse JSON or YAML strings into map variables.
version: '3'
tasks:
task-with-map:
vars:
JSON: '{"a": 1, "b": 2, "c": 3}'
FOO:
ref: "fromJson .JSON"
cmds:
- echo {{.FOO}}
ubuntu@touted-mite:~$ task task-with-map
task: [task-with-map] echo map[a:1 b:2 c:3]
map[a:1 b:2 c:3]